OK , the argument I presented originally went like this - Scandinavian germanic tribes started using fenno-ugric loan word as a taboo word replacement (as in modern est. word for wolf - ´hunt´in. est. - came from german. ´hund´(dog) ,and has almost replaced the orig. taboo word for wolf -´susi´) . And the word was ´´kala´ , which is recognisable in all fenno-ugric languages . Even in kama language in Altaiy mountains the word is ´kola´ (Collinder). The word dates back around 7000 years , maybe more .
But the point was not the age of the word , but the loan mechanism . Taboo word was used persistantly in connection to hope of catching a big fish or sea animal . So in time the loan word started meaning esp. big catch . Nordic pronounciation of ´kala´ would have looked like ´whala´ . So kala - whala - whale . And it boomeranged back to est. language as ´vaal´ .
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I´m not competent to judge this theory , so I just present it .